1. Field of the Invention
The present invention relates to a disk drive device for driving an information recording disk such as a compact disk (CD) or a digital video disk (DVD) loaded onto it and reading and writing information out of and into the disk.
2. Description of the Related Art
A disk drive device is built into a parent apparatus, such as a small computer. A first example of such conventional disk drive device will be below described below with reference to FIG. 8. This example is disclosed in the Japanese Patent Application Laid-Open No. 8-138296.
The disk drive device consists of a body chassis 102 to be fitted to a small computer and a tray 103 on which a disk is to be loaded. To the left side wall of the tray 103 is fitted a left slider 140, and near the right end of the under face of the tray 103 is fitted a right slider 141.
On the other hand, a left slider rail 150 is formed on the left side wall of the body chassis 102, and a right slider rail 151, on the right side wall of the same. By the mutual engagement of these sliders 140 and 141 and slider rails 150 and 151, the tray 103 is supported by the body chassis 102 to be movable in the Y–Y′ direction.
A stage 106 protrudes horizontally outwards from the upper end of the right side wall of the body chassis 102. The top face of the stage 106 is positioned higher than the central bottom face of the body chassis 102.
The disk protective portion 111 of the tray 103 is in a rectangular shape large enough to cover the whole area of the under face of the disk. However, in a state in which the tray 103 is fully pulled out of the body chassis (in an unloaded position), there is a slight gap between the rear edge of the disk protective portion 11 (the edge on the body chassis side) and the front end of the body chassis 102 (the edge on the tray side). This gap is intended to prevent the disk, when it is unloaded from or loaded onto the tray 103, from hitting the body chassis 102.
In a state in which the tray 103 is fully pressed into the body chassis 102 (in a loaded position), the portion of the disk protective portion 111 protruding rightwards from the right slider 141 comes above the stage 106.
In order to minimize the height of this disk drive device illustrated in FIG. 8, it is required to minimize the gap, if any, between the top face of the stage 106 of the body chassis 102 and the under face of the disk protective portion 111 of the tray 103.
Then, when the tray 103 in the unloaded position is pressed into the body chassis 102, the rear end of the disk protective portion 111 hits against the front end of the stage 106 of the body chassis 102, making it impossible to press the tray 103 farther in. This occurs because, when the tray 103 begins to be shifted from the unloaded position into the body chassis 102, the sliders 140 and 141 and the slider rails 150 and 151 are not yet engaged with each other for a sufficient length, and the tray 103 is made liable to oscillate vertically during its shifting.
On the other hand, if it is so arranged that part of the disk protective portion 111 overlaps part of the stage 106 even when the tray 103 is in the unloaded position, the shifting of the tray 103 is not obstructed by the stage 106 of the body chassis 102 when the tray 103 in the unloaded position is pressed into the body chassis 102. In this case, however, there is a fear that the disk may be allowed to hit against the body chassis 102 when the disk is unloaded from, or loaded onto, the tray 103.
Next will be described a second example of conventional disk drive device with reference to FIG. 9. This example is disclosed in the Japanese Patent Application Laid-Open No. 9-223347.
The disk drive device consists of a body chassis 202 fitted to a small computer and a rail tray 203 on which a disk is to be loaded. The tray 203 is supported by the body chassis 202 to be movable in the A-B direction.
To the left and right side walls of the body chassis 202 are fitted fixed side rails 207, and to the left and right side walls of the tray 203 are fitted movable side rails 206. Between these movable side rails 206 and fixed side rails 207 intervene intermediate rails 208.
From the top end of the right side wall the body chassis 202 protrudes a stage 216 outwards horizontally. The top face of the stage 216 is positioned higher than the central bottom face of the body chassis 202.
The disk protective portion 211 of the tray 203 is provided only in the area between the left and right movable side rails 206, and the outer (right) side of the right rail 206 is cut off. This absence of the disk protective portion 211 outside the right rail 206 eliminates the overlapping of the stage 216 and the disk protective portion 211 when the tray 203 is pressed into the body chassis 202, and results in the advantage that the disk drive device can be reduced in height.
However, the portion of the disk loaded on the tray 203 outside the right rail 206 (i.e. the portion overlapping the stage 216) is unprotected and exposed. Moreover, as the width of the disk protective portion 211 is smaller than the full diameter of the disk, the strength of the tray 203 is weakened.